Centrifugal abrading device



Nov. 1938- A. v. HOLLINGSWORTH 2,135,510

CENTRIFUGAL ABRADING DEVICE Original Filed Nov. 14, 1936 2 SheetsSheet l ATTORNEM 1938. A. v. HOLLINGSWORTH 2,135,510

GENTRIFUGAL ABRADING DEVICE Original Filed Nov. 14, 1936 2 Sheets-Sheet 2 INVENTOR ATTORNEY Patented Nov. 8, 1938 CENTRIFUGAL ABRADING nsvros Alfred V. Hollingsworth, Indianapolis, Ind., as-

signor .to The American Foundry Equipment Company, Mishawaka, Ind., a corporation of Delaware Application November 14, 1936,, Serial No. 110,844 Renewed February 8, 1938 15 Claims.

I This invention relates to centrifugal abrading device, and more particularly to an abrasivethrowing device having means associated therewith whereby the direction of discharge of the thrown abrasive can be definitely controlled.

An object of the present invention is to provide positive means for controlling the direction of fiight of abrasive thrown by one or more rapidly revolving blades or throwing surfaces.

Other objects ofthis invention will become apparent as the disclosure proceeds.

According to the present invention, a throwing wheel having one or more abrasive-throwing surfaces or blades is rotatably mounted on a drive shaft. The throwing blades may be supported by. a'side wall member or disk fixed to the end of the drive shaft, The blades are preferably channel-shaped to confine the abrasive within the blade area. The abrasive control 2o means is preferably positioned at the center of a the wheel and preferably the blades extend from the periphery of the wheel inwardly short of the rotating ax sso as to provide a central space or opening within which the control means may be 5 positioned. The control means may comprise-a ported abrasive-receiving member which provides a chamber into which the abrasive is conducted by means of a suitable supply conduit. The abrasive-receiving member is preferably tubular in ,39 form and is fixed to rotate with the wheel: and the tubular side wall thereof is provided with an abrasive .discharge port or opening preferably positioned slightly in advance of each throwing blade.

charge port and means are provided for opening and closing the closures as the ports successively pass through a predetermined arc during rotation of the wheel. The closure-operating means may comprise a normally stationary cam member having a cam surface over which followers operably connected to the respective closure members, may ride. The cam is provided. with a' r'elieved or depressed portion per- 45 mitting movement of the followers to operate the closures thereby opening the ports at the desred predetermined point during rotation of the wheel and thereafter to close the discharge ports when the desired quantity of abrasive has been 0 ejected therethrough. The closure-operating mechanism may be provided with means to positively open thedischarge ports or, if desired, centrifugal force may be relied upon to swing the closure member into open position at the desired 55 predetermined point during rotation, thereafter ,3 Suitable closures are provided for each disto be positively closed by the cam member. Thus the passage of the abrasive from the abrasivecontaining member onto the inner end of the blades can be definitely controlled, so that the directionof flight of the abrasive thrown by the 6 blades can be thereby definitely predetermined and controlled.

Various other features and advantages of the invention will be apparent from the following particular description and from an inspection of 1 th accompanying drawings.

[Although the novel features which are believed to be characteristic of this invention. will be particularly pointed out in the claims appended hereto, the invention itself, as to its objects and advantages, and the manner in which it may be carried out, may be better understood by referring to the following description taken in con- 'nection with the accompanying drawings form-' ing a part thereof, in which:

Fig. 1 is a front elevational view of my improved abrasive-throwin'g machine, certain parts being broken away to expose a portion of the interior construction;

Fig. 2 is an end elevational view of the machine, certain parts being broken away to illustrate certain features of the abrasive control mechanism;

Fig. 3 is a longitudinal cross-sectional view through the abrasive-throwing machine, this view being taken on line 3-3 of Fig. 2;

Fig. 4 is a transverse. cross-sectional view through the abrasive-throwing machine, showing certain details of the abrasive-control mechanism, this view being taken along line 4-4 of Fig. 3; and

Fig. 5 is a fragmentary cross-sectional view of the machine taken along line 55 of Fig. 4, this view particularly illustrating the cam mechanism which operates the abrasive-discharge closures associated with the abrasive-containing member.

Similar reference characters refer to similar parts throughout the several views of the drawings and specifications.

In the drawings, thereis shown, by way of illustration, an abrasive-throwing machine generally comprising a wheel having a plurality of radially arranged abrasive-throwing-blades 12 which extend from the periphery of the wheel inwardly short of the rotating axis thereof so as to define a central opening 0. The throwing blades l2 may be enclosed between two spaced wall members Ill-and H, which are interconnectedin fixed parallel relationship bysuitable means, such as spacers I3 of generally V-shaped wall l4 and a following wall IS, the spacers together defining abrasive passages p therebetween. The spacers may be suitably secured to the side wall members I0 and II as by screws or bolts l8.

The blades I2 may each be mounted upon the advancing wall I4 of the spacer and removably held in position by suitable means, such as set screws 16, which screw into threaded openings provided in the side wall plates l0 and I! and engage a shouldered recess I1 provided in the side edges of each blade. Each blade can be removed and replaced by a proper manipulation of the set screws l6. Each blade is preferably provided with flanges 12a which closely seat against the inside face of the side wall plates l0 and H. It will be understood that the blades 12 may be directly supported from the side wall plates [0 and l l or, if desired, only one side wall plate [8 may be used and the blades mounted directly thereon in a suitable manner. It is also understood that where two side plates l0 and Il are used, any suitable spacing means other than the spacers l3 illustrated may be used within the purview of this invention.

The Wheel is fixed to the end portion 2| of a suitable drive shaft 20 which rotates in a suitable bearing 53. The side wall member ill may be connected to a hub member 22 by means of bolts 24, the hub member 22 being secured to the end portion 2! of the shaft by means of splines 23.

One of the important features of this invention is the provision of mechanism for controlling the direction of discharge of the thrown abrasive. This mechanism preferably comprises a tubular member which extends into the central opening c and which provides an abrasive-receiving chamber. The tubular member may take the form of a cylindrical container having a tubular side wall 25 and an end wall 26. The tubular container may be fixed to rotate with'the blade l2 by means of screws 21 which extend through the end wall 26 and into the hub member 22.

Abrasive discharge ports or openings 28 are provided in the tubular side wall 25, one being provided for each blade [2 of the wheel. It will also be noted that each opening 28 has an axial width which is somewhat less than the width of the blade l2 so as to direct the abrasive escaping through the opening within the confines of the blade flanges l2a. Each abrasive discharge opening 28 is also positioned slightly in advance of the corresponding throwingblade, as clearly shown in Fig. 3, so that abrasive passing out wardly through the discharge opening 28 will drop gently onto the inner end of the advancing blade, thus avoiding serious impact shocks which might otherwise damage the blade and crack up the abrasive. The peripheral length of the openings 28 is such as to permit the desired quantity of abrasive to escape therethrough at each rotation of the wheel.

The abrasive is delivered to the central abrasive-receiving member through a suitable: supply conduit 23 which extends through an opening 30- provided in a plate member 3! which provides a cover closure for the abrasive receiving member. The closure plate 3| may be suitably secured to the side wall 25 as by screws 32.

The direction of flight of the abrasive thrown from the wheel is determined by the clock dial position of the discharge openings 28 when discharging abrasive. To obtain this desired directional control of the thrown abrasive a cl sure form. Each spacer may comprise an advancing or valve member 35 for each of the openings 28 is provided. Each closure member is provided with a seat portion 36 which seats over its corresponding discharge opening 28 so as to prevent escape of abrasive through the opening until the rotating opening arrives at a predetermiend position, as illustrated by way of example in Fig. 3. Mechanism is provided to open and close the closure members 35 at any selected point during the rotation of the wheel.

Each closure member 35 may be operated by a strong and sturdy rock shaft 38 which extends through the side plate l0 and the hub member 22 of the wheel, suitable bearings being provided to permit free rocking movement thereof. One end of each rock shaft 38 is suitably fixed or secured to a collar 31 provided on the corresponding closure member 35. Rocking movement of the shaft 38 will swing the closure member 35 into open or closed position, as desired. Rocking movement is given to the operating shafts 38 by a cam member 45 which is normally held in stationary position. The cam member 45 may be provided with a collar portion 49 which seats over a'bearing collar 58 which is secured to the bearing 53 in any suitable manner. For purposes of illustration, I have illustrated the collar 50 as provided with an outwardly extending flange 55 which is secured as by bolts 54 to an outwardly extending flange 55 provided on the bearing 53. The reduced portion 46 of the 'drive shaft 20 extends through the bearing collar 50 and through the cam member 45. The cam member 45 may be adjustably secured to the bearing collar 50 by suitable means, such as set screws 52.

Referring more particularly to Figs. .2, 4 and 5, the opposite end of each operating shaft 38 is provided with a follower which rides over the cam surface of the cam member 45. Each follower may comprise a crank arm 40 which is provided with a shoe or roller 4| which rides over the outer periphery of the cam 45. The roller 4| may be rotatably mounted on a suitable stud 42 projecting laterally from the free end of its associated crank arm 40. The end portion 39 of each shaft extends through and is fixedly secured to a collar 42 provided at one end of its associated crank arm 40.

It will be noted that the cam member 45 is provided with a cam surface 41 which is substantially circular and depressed portion. 48 over which each of the followers or rollers 4| successively passes as the wheel rotates. Each of the closure members 35 is held in closed seating position against its corresponding opening 28 when its associated follower passes over the circular cam surface 41. When the rollers successively reach the depressed portion 48 of the cam surface, centrifugal force is free to act upon the closure members 35 so as to throw the closure members 35 outwardly from their associated openings 28, as shown in Fig. 3, so as to permit the escape of a quantity of abrasive through the opening. The depressed portion 48 of the cam surface is so shaped as to permit the closure member 35 to remain in'open position for a sufficient period to permit the desired quantity of abrasive to escape. If desired, more positive means than the action of centrifugal force may be provided for openingvthe closure members 35 at the desired predeterminedpoint during rota; tion. By way of example, a cam slot (not shown) may be provided in the cam member 45 through which the followers or rollers 4! move,

1 abrasive onto the inner end of the blades.

so as to positively cause the roller 4| to roll along the, depressed portion 48 of the cam track, re-

.sulting in a positive opening and closing of the closure members 35. Again, by way of example, the cam member 45 may be provided with an overhanging ledge portion 59 adjacent the depressed portion 48, the ledge portion engaging the topof the roller and forcing it into the depressed groove 60 provided between the depressed cam surface 48 and the overhanging ledge portion 59. The overhanging ledge portion 59 may be integrally formed with or secured to the cam member 45, as illustrated in Figs. 4 and 5, as by a web portion 6|. It is also understood that suitable resilient means may also be provided to positively control the opening and closing of the closure members 35.

A cup-shaped casing 10 may be provided to enclose the cam member 45 and associated closure operating mechanism. The casing 10 extends between the rotating hub member 22 and the stathe collar portion 49 of the cam member 45. The

space within the casing 10 may be filled with a lubricant so that the rapidly moving followers 4| are amply lubricated.

The operation of the wheel is as follows: Abrasive a is fed into the abrasive-receiving member through the feed pipe 29 and the shaft 20 is rotated to revolve the wheel at sufficient speed to throw the abrasive at an abrading veicc-- ity. In the cleaning of hard metallic castings and iorgings it is generally desirable to give the abrasive as it leaves the wheel a velocity of 9000 to 15000 lineal feet per minute. The desired speed of the thrown abrasive will of course vary within wide limits depending upon the character of the abrasive, the character of the surface to be cleaned, the speed with which cleaning is to be effected and other conditions. In this connection it will be noted that the term abrasive as used herein encompasses such materials as cracked steel grit, steel shot, quartz sand and similar materials used to clean hard metallic surfaces or anneal the surface through the impinging action of the material thrown.

To throw the abrasive at the desired velocities above noted a wheel measuring approximately 20' in diameter from blade tip to blade tip should be rotated from 1800 to 2500 R. P. M. For most uses satisfactory abrading action can be effected by rotating the wheel of this diameter at approximately 2200 revolutions per minute (R. P. M The direction of discharge of the thrown abrasive is determined by the point of entry of the In the machine herein shown this is accordingly determined by the clock-dial position at which the closure members 35 are successively swung into open position so as to permit ejection of the abrasive through their associated discharge openings 28. The proper clock-dial position at which the closure or valve members 35 should be successively opened and closed to obtain a predetermined directional discharge from the wheel is of course aifected by the length of the revolving blade, the speed of rotation of the blade, the

.tions.

surface characteristic of the blade, the speed of the abrasive as it is initially deposited on the inner end of the blade, and possibly other condi- The proper clock-dial position at which the closure or valve members 35 should be swung open can be quickly determined by test or can be computed empirically by giving due consideration of the factors above noted. By way of example, where the abrasive is not forcibly thrown out of the open discharge opening 28 in the ring member by substantial force it has been found that a downward flight of the thrown abrasive can be affected by exposing the openings 28 at the 8 or 9 oclock position on the clock-dial, the wheel rotating clockwise. By providing an agitator or impeller within the ring member, the abrasive can be thrown out through the discharging opening therein at a speed which approximates the speed of rotation of the inner end'of the throwing blades |2Qunder such conditions the opening should possibly be opened for discharge at the 11 or 12 oclock position to obtain downward discharge of the abrasive.

The direction of flight of 'the thrown abrasive can be adjusted and controlled by adjusting the clock-dial position of the depressed portion 48 of the cam member 45 which freely rides on a reduced portion 46 of the-drive shaft 20. Adjustment of the cam member 45 so as to place the depressed portion 48 in any desired clock-dial position can be accomplished by loosening the set screws 52 which clamp the collar portion 49 of the cam member 45, thus rotating the cam member to the proper positlonj and then resetting the screws 52. It will be noted that the circular cam surface 41 of the cam member 45 retains the closure members 35 in closed seating position over their associated discharge openings 28 during the period at which the followers 4| associated with the respective closure members pass over the cam surface 41. When the closure member operating followers successively reach the depressed cam surface 48 the closure members 35 are immediately swung outwardly into open position motivated by centrifugal force acting thereon, or they may be positively swung open when the followers 4| come into contact with the guide member 59.

Thus it is seen that the discharge openings 28 may be opened so as to discharge abrasive therefrom at any desired clock-dial position by making a corresponding clock-dial adjustment of the depressed portion 48 of the cam member 4 5. This can be easily and quickly accomplished byremoving the casing 10 and loosening the set screws 52, rotating the collar portion 49 of the cam member 45 to the proper position and resetting the set screws 52 so as to firmly en gage the bearing collar 50. While I have shown in Fig. 3 for purposes of illustration the abrasive discharging of the wheel downwardly, the abrasive can also be thrown from the wheel in an upward direction or to the right or to the left of the wheel as desired by making the proper adjustment of the cam member 45. Thus complete directional control of the thrown abrasive is accomplished.

It will be noted that the throwing blades |2 are removable and replaceable and may be easily removed when worn by loosening the set screws I6 and thereafter inserting a fresh set of blades. The outer ends of the blades are of course subjected to the greatest wear and, if desired, the blades can be reversed end to end when the outer ends become worn so that the full use of the bladescan be obtained before they are finally discarded. The flanges l3 of I the 'blades retain the abrasive out of wearing contact with the side wall members Ill and II ed as to operate with as little friction as possible.

While certain novel features of the invention have been disclosed and are pointed out in the annexed claims, it will be understood that various omissions, substitutions and modifications may be made by those skilled in the art without departing from the spirit of the invention.

What is claimed is: 1. In a centrifugal abrading device, a rotatable abrasive-throwing member, a ported member forming an abrasive-receiving chamber adjacent the axis of rotation of said member, and port-closing means operated in timed relation to the rotation of said member to provide intermittent passage ofabrasive from said chamber into the path of rotation of said throwing member for controlling the direction of discharge of abrasive from said throwing member.

2. In a centrifugal abrading device, a rotatable abrasive-throwing surface, a member forming a central abrasive-throwing chamber therein, said member having ports permitting passage of abrasive from said chamber outwardly, closures for said ports, and means operating said closures to permit passage'of abrasive through each port during a predetermined arc only and thereby controlling the direction of discharge of abrasive from said rotating surface.

3. In a'centrifugal abrading device, a rotatable abrasive-throwing blade, a member forming a central abrasive-receiving chamber therein, said member having ports permitting passage of abrasive outwardly into the path of rotation of said blade, closures for said ports, and means operating said closures in timed relation with the rotation of said blade to control the direction of discharge of the abrasive therefrom.

4. In a centrifugal abrading device, a rotatable abrasive-throwing wheel, said wheel having abrasive-throwing .blades extending toward the periphery thereof,. a member forming a central abrasive-receiving chamber, said member having a port adjacent the inner end of each of said blades through which abrasive may be discharged from said chamber to said blades, closures for said ports, andmeans operating said closures to permit passage of abrasive through eachrotating port as said ports pass successively through a predetermined arc thereby con-, trolling the direction of discharge of abrasive from said blades.

5. In a centrifugal abrading device, a rotatable abrasive-throwing wheel, said wheel having abrasive-throwing blades extending toward the periphery thereof, a member forming a central abrasive-receiving chamber therein, said member having a port adjacent the inner end of each of said blades through which abrasive may be discharged from said chamber to said blades, closures for said ports, and means operating said closures in timed relation with the rotation of the wheel to control the direction of discharge of the abrasive therefrom. 6. In a centrifugal abrading device, arotatable abrasive-throwing wheel, a member forming a central abrasive-receiving chamber therein, a plurality of surfaces for conducting abrasive from said chamber toward the periphery of the wheel, said member having a port adjacent the inner end of each of said surfaces through which abrasive may be discharged from said chamber into the path of rotation of said surfaces, closures for said ports, and means operating said closures to permit passage of abrasive through each port only as said ports successively rotatethrough a predetermined arc, thereby to control the direction of discharge of abrasive from the wheel.

7. In a centrifugal abrading device, a rotatable abrasive-throwing wheel, said wheel having abrasive-throwing blades radiating outwardly toward the periphery thereof, a member centrally located in said wheel and rotatable therewith, said member forming an abrasive-receiving chamber and having a port adjacent the inner end of each of said blades through which abrasive may be discharged from said chamber to said blades, closures for said ports, and means operating said closures to permit passage of abrasive through each port as said ports successively rotate through a predetermined are thereby to control the direction of discharge of abrasive therefrom.

8. In a centrifugal abrading device, a rotatable abrasive-throwing wheel, said wheel having abrasive-throwing blades extending outwardly toward the periphery thereof, a member forming a central abrasive-receiving chamber therein, said member having a port adjacent the inner end of each of said blades through which abrasive may be discharged from said chamber to said blades,

closures for said ports, a stationary cam, and a follower operatively connected to each of said closures and engaging said cam, said followers operating said closures to control the direction of discharge of the abrasive from said wheel.

9. In a centrifugal abrading device, a rotatable abrasive-throwing wheel, said wheel having abrasive-throwing blades extending outwardly toward the periphery othereof, a member forming a central abrasive-receiving chamber therein, said member having a port adjacent the inner end of said chamber, rock shafts on which said closures are mounted, said rock shafts being carried by a rotating portion of said wheel, a stationary cam, and followers mounted on said rock shafts and engaging said cam, said cam being shaped to open and close each closure at a predetermined point in the rotation of the wheel.

11. In a centrifugal abrading device, a rotatable abrasive-throwing wheel having a hub, a rotatable shaft on which said wheel is mounted, a

ported member forming a central abrasive-receiving chamber in said wheel, a plurality of rockshafts extending longitudinally through said hub eccentrically of the axis of said first-mentioned shaft, a stationary cam, a follower on each of said rock shafts engaging said cam, and port closures secured to the opposite ends of said rock shafts and adapted to be opened and closed by the action of said cam at a predetermined point in the rotation of the wheel to thereby control the outward flow of abrasive from said ported member.

12. In a, centrifugal abrading device, a rotatable abrasive-throwing wheel having a ported abrasive receiving member adjacent the center thereof, closures for the ports of said member, a cam, and followers operatively connected to said closures and engaging said cam, said followers normally being held in engagement with said cam by centrifugal force acting upon said closures.

13. In a centrifugal abrading device, a rotatable abrasive-throwing wheel having a ported abrasive-receiving member adjacent the center thereof, closures for the ports of said member, a cam, and followers operatively connected to said closures and engaging said cam, said followers normally being held in engagement with said cam by centrifugal force acting upon said closures, said cam having a relieved portion permitting movement of said followers to open said closures by centrifugal force at a predetermined point in the rotation of the wheel.

14. In a centrifugal abrading device, a rotatable abrasive-throwing wheel having a ported abrasive-throwing member adjacent the center thereof, closures for the ports of said member urged toward open position by the centrifugal force of the rotation of the wheel, and restraining means opposing said centrifugal force to maintain said closures in closed position throughout all but a predetermined portion of the rotation of the wheel.

15. In a centrifugal abrading device, a rotatable abrasive-throwing wheel having a ported abrasive-receiving member adjacent the center thereof, closures for the ports of said member movable to port-closing and port-opening positions and urged toward one of said positions by the centrifugal force of the rotation of the wheel, and restraining means opposing said centrifugal force to maintain said closures in the other of i said positions throughout all but a predetermined portion of the rotation of the wheel.

ALFRED V. HOLLINGSWORTH. 

